We propose to work closely with the Kenyan Ministry of Health's National AIDS and STD Control Program (NASCOP), the University of Nairobi, and the Kenya Medical Research Institute to incorporate male partners into antenatal care by providing home-based partner education and HIV testing to families as part of routine pregnancy services. Involvement of men during the antenatal and postpartum period, including HIV testing of male partners, can have substantial benefits for both HIV-infected and uninfected women and their infants. Male participation in antenatal care has been associated with increased uptake of prevention of mother-to-child transmission (PMTCT) interventions among HIV-infected women and has a survival benefit for children. By providing home-based services, HIV-1-infected men who would otherwise not learn their status or would delay seeking treatment will be identified and engage in HIV care, reducing risk of HIV transmission to uninfected female partners. Child health overall will be improved through leveraging this opportunity to interact wit men and promote the benefits of facility delivery, exclusive breastfeeding, and postpartum contraception. For Aim 1, we hypothesize that educating men during their partner's pregnancy and providing HIV testing to male partners will reduce risky sexual behavior, increase facility deliveries and contraception use postpartum, improve breastfeeding practices, and increase PMTCT uptake and antiretroviral adherence. We propose to test this among 300 pregnant HIV-1-uninfected women and 100 HIV-1-infected women in Western Kenya using a randomized clinical trial design of home-based partner education and HIV testing (HPET) versus standard antenatal care (ANC). Outcomes will be determined during clinic visits for women in both arms at 6 and 14 weeks and for men and women during a home visit at 6 months postpartum. Aim 2 focuses on uptake and timing of HIV care and treatment services for HIV-1-infected men post-HPET and compares male partner disclosure of status, initiation of TMP-SMX, and uptake of ART between HPET and standard ANC arms. In Aim 3 we will estimate the incremental cost per pregnant woman and the incremental cost-effectiveness per infant HIV infection averted, maternal HIV infection averted, and HIV-related death and disability adjusted life- year (DALY) averted. Incremental cost-effectiveness will be assessed from payer and societal perspectives and costs of providing HPET for HIV-infected versus uninfected women, as well as testing multiple family members will be examined. Data from all three aims will be critical to determine whether HPET can be scaled up by the Kenya Ministry of Health to prevent maternal and infant HIV-1 acquisition and enhance HIV-free child survival. While the proposed HPET intervention is founded on established programs in home-based counseling and HIV testing in Western Kenya, it is novel in that it would shift the PMTCT paradigm of HIV prevention among women and infants to include men, using the antenatal care setting to address a larger heterosexual HIV prevention agenda while filling important gaps preventing vertical HIV-1 transmission.